Heat oven to 350°F. Coat a 5- to 6-cup baking dish with butter or nonstick cooking spray.
In a food processor or high-powered blender, blend half the corn until finely chopped.
Slice the butter into a few pieces. In a large sauté pan over medium heat, melt the butter and continue to cook it, stirring frequently, until light brown flecks appear and it smells toasty.
Pour off 2 tablespoons of the brown butter into a small dish and set aside.
Add whole corn kernels, blended corn, salt, and cayenne to the brown butter in the pan and cook over medium-high heat, stirring, for 4 to 5 minutes, until the corn is tender and brighter yellow.
Scrape the corn and brown butter into a large bowl and whisk in sour cream. Let it cool if still piping hot.
Whisk in eggs until well-combined. Sprinkle sugar and baking powder over batter surface and whisk thoroughly. Add flour and cornmeal and mix until just combined.
Scrape batter into prepared dish.
Bake for 15 to 20 minutes, until a toothpick inserted into the center comes out batter-free.
Immediately drizzle reserved brown butter over batter. Add a few flakes of sea salt too, if you wish. Eat warm.